Incident Overview
A pilot and passenger were on a local flight at night. Personnel at the airport noted that the runway lights had been activated, but no aircraft was seen to land. The aircraft was found the next morning about six miles northeast of the airport, where it had hit trees and crashed.
Investigation Findings
An investigation revealed that the aircraft impacted trees while in a shallow descent. Examination of the propeller showed a lack of rotational scarring; only one blade was deformed and only one blade contained leading edge nicks. The flaps were found in the fully extended (30-degree) position, but the flap indicator showed only 10 degrees of flaps.
About eight gallons of fuel was found in each wing tank. A check of the engine revealed a lack of compression in the number three cylinder due to a broken exhaust valve spring. No other pre-accident anomalies were found.
Occupant Restraint Use
The pilot and passenger were not wearing their available shoulder harnesses.
Summary
No probable cause was stated in the source. The accident involved a night local flight, tree impact, engine malfunction (broken exhaust valve spring), flap indicator discrepancy, and non-use of shoulder harnesses.